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Gysin G, Urbano P, Brandner-Garrod L, Begum S, Kristan M, Walker T, Hernández C, Ramírez JD, Messenger LA. Towards environmental detection of Chagas disease vectors and pathogen. Sci Rep 2022; 12:9849. [PMID: 35701602 PMCID: PMC9194887 DOI: 10.1038/s41598-022-14051-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/31/2022] [Indexed: 12/02/2022] Open
Abstract
Chagas disease vector control relies on prompt, accurate identification of houses infested with triatomine bugs for targeted insecticide spraying. However, most current detection methods are laborious, lack standardization, have substantial operational costs and limited sensitivity, especially when triatomine bug densities are low or highly focal. We evaluated the use of FTA cards or cotton-tipped swabs to develop a low-technology, non-invasive method of detecting environmental DNA (eDNA) from both triatomine bugs and Trypanosoma cruzi for use in household surveillance in eastern Colombia, an endemic region for Chagas disease. Study findings demonstrated that Rhodnius prolixus eDNA, collected on FTA cards, can be detected at temperatures between 21 and 32 °C, when deposited by individual, recently blood-fed nymphs. Additionally, cotton-tipped swabs are a feasible tool for field sampling of both T. cruzi and R. prolixus eDNA in infested households and may be preferable due to their lower cost. eDNA detection should not yet replace current surveillance tools, but instead be evaluated in parallel as a more sensitive, higher-throughput, lower cost alternative. eDNA collection requires virtually no skills or resources in situ and therefore has the potential to be implemented in endemic communities as part of citizen science initiatives to control Chagas disease transmission.
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Affiliation(s)
- Grace Gysin
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Plutarco Urbano
- Centro de Investigaciones en Microbiología y Biotecnología-UR (CIMBIUR), Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia.,Grupo de Investigaciones Biológicas de la Orinoquia, Universidad Internacional del Trópico Americano (Unitrópico), Yopal, Colombia
| | - Luke Brandner-Garrod
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Shahida Begum
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Mojca Kristan
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Thomas Walker
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Carolina Hernández
- Centro de Investigaciones en Microbiología y Biotecnología-UR (CIMBIUR), Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia.,Centro de Tecnología en Salud (CETESA), Innovaseq SAS, Bogotá, Colombia
| | - Juan David Ramírez
- Centro de Investigaciones en Microbiología y Biotecnología-UR (CIMBIUR), Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia.,Molecular Microbiology Laboratory, Department of Pathology, Molecular and Cell-Based Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Louisa A Messenger
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
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Blomstrand BM, Enemark HL, Steinshamn H, Aasen IM, Johanssen JRE, Athanasiadou S, Thamsborg SM, Sørheim KM. Administration of spruce bark (Picea abies) extracts in young lambs exhibits anticoccidial effects but reduces milk intake and body weight gain. Acta Vet Scand 2022; 64:10. [PMID: 35461282 PMCID: PMC9034609 DOI: 10.1186/s13028-022-00629-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/30/2022] [Indexed: 11/27/2022] Open
Abstract
Background Eimeria spp. are widespread apicomplexan parasites known to cause coccidiosis in livestock, resulting in reduced animal welfare and productivity, particularly in sheep. The treatment options are limited, and there is an emerging development of resistance against registered pharmaceuticals. Spruce bark is rich in plant secondary metabolites (PSM), such as condensed tannins, which are bioactive compounds previously shown to have antiparasitic activity. Here, we examined the anticoccidial properties of bark extract of Norway spruce (Picea abies) against a field isolate of ovine Eimeria spp. by treating Eimeria-infected pre-ruminant lambs with water-extracted bark daily for 12 days. We hypothesised that the bark extract would reduce the faecal oocyst excretion and, consequently, the severity of diarrhoea. Results Oral administration of spruce bark extract significantly reduced the excretion of Eimeria oocysts in milk-fed lambs post treatment till the end of the trial 22 days post infection. This difference in oocyst excretion between the treated and the untreated infected animals increased with time. Compared to the untreated and the sham-infected control group, the group treated with bark extract had softer faeces and reduced milk intake during the treatment period. After discontinuing the treatment, the treated animals got a more solid and formed faeces compared to that of the untreated control group, and the milk intake increased to the level of the sham-infected, untreated control group. The bark extract treated animals had a lower body weight and a lower mean daily body weight gain throughout the whole duration of the experiment. Conclusions Bark extract from Norway spruce showed marked anticoccidial properties by reducing the faecal oocyst count and associated diarrhoea in young lambs. Simultaneously we experienced detrimental effects of the treatment, displayed as reduced feed intake and daily body weight gain. Therefore, we suggest conducting similar studies with lower bark extract dosage to explore the possibilities of a better trade-off to reduce the negative impact while maintaining the antiparasitic effect. Supplementary Information The online version contains supplementary material available at 10.1186/s13028-022-00629-y.
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Insect Fluctuating Asymmetry: An Example in Bolivian Peridomestic Populations of Triatoma infestans (Klug, 1834) (Hemiptera: Reduviidae). Symmetry (Basel) 2022. [DOI: 10.3390/sym14030526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Fluctuating asymmetry (FA) is a morphometric tool used to measure developmental instability in organisms which have been exposed to stress or other adverse conditions. Phenotypic variability in response to stressors are the result of interactions between genomes and the environment, acting in a noisy developmental system. Most of the organisms have bilateral symmetry with a repetition of structures in different positions or orientations; asymmetrical variation has been a morphological response associated with insecticide application inducing disturbances in endocrinal system product of the chemicals. Triatoma infestans (is the main vector of Chagas disease in South America. The availability of food sources varies for populations of T. infestans living in different habitats; insects that inhabit the intradomicile feed preferentially on human blood, whereas insects that develop in the peridomicile feed on the blood of the other mammals and birds. The following research evaluate the FA to the different ecotopes in two geographical areas of Chuquisaca Bolivia; Yamparáez/Sotomayor of the high inter-Andean valleys and Huacaya/Imbochi of the boreal Chaco and a CIPEIN laboratory strain population. A combination of advanced morphometrics tools and multivariate analysis were used to quantify the levels of asymmetry produced by pyretroid near to the peridomiciles in Bolivia. Populations from Yamparáez/Sotomayor were found to have higher levels of FA which the combination of environmental conditions such as low temperatures avoid greater permanence in the habitat and more exposition to insecticide. A better understanding of the combination of these tools will allow researchers to implement better public policies to regulate insecticide applications and to understand how certain organisms adapt to multiple stressors.
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Rojas de Arias A, Messenger LA, Rolon M, Vega MC, Acosta N, Villalba C, Marcet PL. Dynamics of Triatoma infestans populations in the Paraguayan Chaco: Population genetic analysis of household reinfestation following vector control. PLoS One 2022; 17:e0263465. [PMID: 35143523 PMCID: PMC8830694 DOI: 10.1371/journal.pone.0263465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 01/19/2022] [Indexed: 11/28/2022] Open
Abstract
Background Although domestic infestations by Triatoma infestans have been successfully controlled across Latin America, in areas of the Gran Chaco region, recurrent post-spraying house colonization continues to be a significant challenge, jeopardizing Chagas disease vector control and maintaining active Trypanosoma cruzi transmission. Methodology/Principal findings To investigate the dynamics of triatomine reinfestation in a rural area of the Paraguayan Chaco, genetic characterization (based on 10 microsatellite loci and cytochrome B sequence polymorphisms) was performed on baseline and reinfestant T. infestans (n = 138) from four indigenous communities and adjacent sylvatic sites. House quality and basic economic activities were assessed across the four communities. Significant genetic differentiation was detected among all baseline triatomine populations. Faster reinfestation was observed in the communities with higher infestation rates pre-spraying. Baseline and reinfestant populations from the same communities were not genetically different, but two potentially distinct processes of reinfestation were evident. In Campo Largo, the reinfestant population was likely founded by domestic survivor foci, with reduced genetic diversity relative to the baseline population. However, in 12 de Junio, reinfestant bugs were likely derived from different sources, including survivors from the pre-spraying population and sympatric sylvatic bugs, indicative of gene-flow between these habitats, likely driven by high human mobility and economic activities in adjacent sylvatic areas. Conclusions/Significance Our results demonstrate that sylvatic T. infestans threatens vector control strategies, either as a reinfestation source or by providing a temporary refuge during insecticide spraying. Passive anthropogenic importation of T. infestans and active human interactions with neighboring forested areas also played a role in recolonization. Optimization of spraying, integrated community development and close monitoring of sylvatic areas should be considered when implementing vector control activities in the Gran Chaco.
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Affiliation(s)
- Antonieta Rojas de Arias
- Centro para el Desarrollo de la Investigación Científica (CEDIC/Díaz Gill Medicina Laboratorial /FMB), Asunción, Paraguay
- * E-mail:
| | - Louisa Alexandra Messenger
- Division of Parasitic Diseases and Malaria (DPDM), Centers for Diseases Control and Prevention (CDC), Entomology Branch, Atlanta, GA, United States of America
- American Society for Microbiology, NW Washington, DC, United States of America
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Miriam Rolon
- Centro para el Desarrollo de la Investigación Científica (CEDIC/Díaz Gill Medicina Laboratorial /FMB), Asunción, Paraguay
| | - María Celeste Vega
- Centro para el Desarrollo de la Investigación Científica (CEDIC/Díaz Gill Medicina Laboratorial /FMB), Asunción, Paraguay
| | - Nidia Acosta
- Departamento de Medicina Tropical, Instituto de Investigaciones en Ciencias de la Salud, UNA, Asuncion, Paraguay
| | - Cesia Villalba
- Programa Nacional de Control de la Enfermedad de Chagas (SENEPA), Asunción, Paraguay
| | - Paula L. Marcet
- Division of Parasitic Diseases and Malaria (DPDM), Centers for Diseases Control and Prevention (CDC), Entomology Branch, Atlanta, GA, United States of America
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Chacón F, Muñoz-San Martín C, Bacigalupo A, Álvarez-Duhart B, Solís R, Cattan PE. Trypanosoma cruzi Parasite Load Modulates the Circadian Activity Pattern of Triatoma infestans. INSECTS 2022; 13:insects13010076. [PMID: 35055920 PMCID: PMC8777832 DOI: 10.3390/insects13010076] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 12/28/2021] [Accepted: 01/06/2022] [Indexed: 01/22/2023]
Abstract
Simple Summary We studied the locomotor activity of one of the kissing bug species that transmit the Chagas disease-causing parasite in humans, which usually bites during the night. To date, no other reports researching its behavior take into account the amount of parasites inside the kissing bug; however, some studies have demonstrated that the presence of parasites modifies the activity of some kissing bug species. We recorded their movements in light and dark conditions after part of the insects fed on mammals that had the parasite and others fed on those that did not have the parasite. Later, their amounts of parasites were quantified. We found that, compared with insects with no parasites, kissing bugs with higher parasite amounts increase the number of times they move and the distance they travel, especially during daylight hours. This could imply that the insect increases its time searching for a food source when it is infected with a higher number of parasites, and this could increase the risk of transmission of the parasite to people by the kissing bug. Abstract American trypanosomiasis is a disease caused by the flagellate protozoan Trypanosoma cruzi, which is transmitted mainly in endemic areas by blood-sucking triatomine vectors. Triatoma infestans is the most important vector in the southern cone of South America, exhibiting a nocturnal host-seeking behavior. It has been previously documented that the parasite produces changes in some triatomine species, but this is the first time that the behavior of a vector has been evaluated in relation to its parasite load. After comparing the movement events and distance traveled of infected and non-infected T. infestans, we evaluated the change produced by different T. cruzi parasite loads on its circadian locomotor activity. We observed differences between infected and non-infected triatomines, and a significant relation between the parasite load and the increase in locomotor activity of T. infestans, which was accentuated during the photophase. This could have direct implications on the transmission of T. cruzi, as the increased movement and distance traveled could enhance the contact of the vector with the host, while increasing the predation risk for the vector, which could both constitute a risk for vectorial and oral transmission to mammals.
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Affiliation(s)
- Francisco Chacón
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (C.M.-S.M.); (A.B.); (B.Á.-D.)
- Programa de Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Campus Sur, Universidad de Chile, Santiago 8150215, Chile
| | - Catalina Muñoz-San Martín
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (C.M.-S.M.); (A.B.); (B.Á.-D.)
- Núcleo de Investigaciones Aplicadas en Ciencias Veterinarias y Agronómicas, Campus Providencia, Universidad de las Américas, Santiago 7500975, Chile
| | - Antonella Bacigalupo
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (C.M.-S.M.); (A.B.); (B.Á.-D.)
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Bárbara Álvarez-Duhart
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (C.M.-S.M.); (A.B.); (B.Á.-D.)
| | - Rigoberto Solís
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (C.M.-S.M.); (A.B.); (B.Á.-D.)
- Correspondence: (R.S.); (P.E.C.); Tel.: +562-2978-5527 (R.S.); +562-2978-5629 (P.E.C.)
| | - Pedro E. Cattan
- Laboratorio de Ecología, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile; (F.C.); (C.M.-S.M.); (A.B.); (B.Á.-D.)
- Correspondence: (R.S.); (P.E.C.); Tel.: +562-2978-5527 (R.S.); +562-2978-5629 (P.E.C.)
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6
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Gorla DE, Xiao-Nong Z, Diotaiuti L, Khoa PT, Waleckx E, Souza RDCMD, Qin L, Lam TX, Freilij H. Different profiles and epidemiological scenarios: past, present and future. Mem Inst Oswaldo Cruz 2022; 117:e200409. [PMID: 35613154 PMCID: PMC9126320 DOI: 10.1590/0074-02760200409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 01/13/2021] [Indexed: 11/22/2022] Open
Abstract
The multiplicity of epidemiological scenarios shown by Chagas Disease, derived from multiple transmission routes of the aetiological agent, occurring on multiple geo-ecobiosocial settings determines the complexity of the disease and reveal the difficulties for its control. From the first description of the link between the parasite, the vector and its domestic habitat and the disease that Carlos Chagas made in 1909, the epidemiological scenarios of the American Trypanosomiasis has shown a dynamic increasing complexity. These scenarios changed with time and geography because of new understandings of the disease from multiple studies, because of policies change at the national and international levels and because human movements brought the parasite and vectors to new geographies. Paradigms that seemed solid at a time were broken down, and we learnt about the global dispersion of Trypanosoma cruzi infection, the multiplicity of transmission routes, that the infection can be cured, and that triatomines are not only a health threat in Latin America. We consider the multiple epidemiological scenarios through the different T. cruzi transmission routes, with or without the participation of a Triatominae vector. We then consider the scenario of regions with vectors without the parasite, to finish with the consideration of future prospects.
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Affiliation(s)
| | | | | | - Pham Thi Khoa
- Science Services of Insect Joint Stock Company, Viet Nam
| | - Etienne Waleckx
- Université de Montpellier, France; Universidad Autónoma de Yucatán, Mexico
| | | | - Liu Qin
- Shanghai Jiao Tong University, China
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Rojas-Cortez M, Pinazo MJ, Gascon J, Gamarra E, Grageda RM, Fernandez R, Rueda E, Pinto J, Anzoleaga HM, Caballero YE, Urioste GS, Sanchez J, Saravia R, Castellon M, Garcia W, Daza LO, Mur IG, Lozano D, Carvalho-Costa FA, Monteiro FA, Torrico F. Community-based entomological surveillance in three Chagas disease-endemic regions in sub-Andean Bolivia. Trans R Soc Trop Med Hyg 2021; 115:1251-1259. [PMID: 34580735 DOI: 10.1093/trstmh/trab150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 08/29/2021] [Accepted: 09/15/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Chagas disease is endemic throughout most of Bolivia, with prevalence rates of 25% observed in some geographic areas located mainly in the sub-Andean region. METHODS Community-based entomological surveillance was carried out in the sub-Andean departments of Cochabamba (municipalities of Cochabamba, Punata and Sacaba), Tarija (municipality of Tarija) and Chuquisaca (municipality of Sucre). The surveillance parameters evaluated were: (i) the proportion of cards with the presence of triatomines; (ii) the distribution of positive cards by area; and (iii) the proportion of cards with the presence of infected triatomines. RESULTS Of the cards returned, in 852 (3.1%) there was a mention of the presence of triatomines. The species Triatoma infestans, Triatoma sordida and Triatoma guasayana were identified in 812 (95.3%), 39 (4.6%) and 1 (0.1%), respectively. The median monthly positivity rate of the cards during 2011-2018 was higher in Punata (9.1%; IQR=3.2-15.4%). The median monthly rate was highest in 2012 (2.7%; IQR=0-5.6%). Fifty positive cards (5.8%) presented insects that were positive for trypanosomatids, mainly in Cochabamba and Punata. CONCLUSIONS The report of triatomines foci by inhabitants represents an effective surveillance system coordinated by a network of specialized and multidisciplinary health centers. These strategies, which should be included in the health policies of endemic countries, enable extending and deepening the dialogue among technicians, communities and their local authorities.
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Affiliation(s)
| | | | - Joaquim Gascon
- ISGlobal, Barcelona, Hospital Clinic - Universitat de Barcelona, Spain
| | - Enzo Gamarra
- Ministerio de Salud, Programa Nacional de Chagas, Bolivia
| | | | | | | | - Jimy Pinto
- Fundación CEADES, Cochabamba, Bolivia.,Centro Plataforma Chagas Cercado, Cochabamba
| | | | | | - Gloria Sandy Urioste
- Fundación CEADES, Cochabamba, Bolivia.,Centro Plataforma Chagas Sacaba, Cochabamba
| | - Jareth Sanchez
- Fundación CEADES, Cochabamba, Bolivia.,Centro Plataforma Chagas Punata, Cochabamba
| | | | | | - Wilson Garcia
- Fundación CEADES, Cochabamba, Bolivia.,Centro Plataforma Chagas Sucre, Chuquisaca
| | - Lourdes Ortiz Daza
- Centro Plataforma Chagas Tarija.,Universidad Juan Misael Saracho, Tarija
| | | | | | - Filipe Anibal Carvalho-Costa
- Labóratory of Molecular Epidemiology and Systemátics, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Fernando Araújo Monteiro
- Labóratory of Molecular Epidemiology and Systemátics, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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Cardozo M, Fiad FG, Crocco LB, Gorla DE. Effect of habitat fragmentation on rural house invasion by sylvatic triatomines: A multiple landscape-scale approach. PLoS Negl Trop Dis 2021; 15:e0009579. [PMID: 34260588 PMCID: PMC8312942 DOI: 10.1371/journal.pntd.0009579] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 07/26/2021] [Accepted: 06/21/2021] [Indexed: 11/20/2022] Open
Abstract
After the decrease of the relative importance of Triatoma infestans, a number of studies reported the occurrence of sylvatic triatomines dispersing actively to domestic environments in the dry western Chaco Region of Argentina. Anthropic modification of the landscape is mentioned as one of the main causes of the increase in domicile invasion. The aim of this study was to describe the occurrence and frequency of sylvatic triatomines invading rural houses, and to evaluate the effect of habitat fragmentation and other ecological factors on the invasion of rural houses in central Argentina. We hypothesized that the decrease in food sources and the loss of wild ecotopes, as a consequence of habitat fragmentation, increase the chances of invasion by triatomines. The entomological data was collected by community-based vector surveillance during fieldwork carried out between 2017-2020, over 131 houses located in fourteen rural communities in the northwest of Córdoba Province (central Argentina). We used generalized linear models to evaluate the effect of (i) the environmental anthropic disturbance in the study area, (ii) the composition and configuration of the landscape surrounding the house, (iii) the spatial arrangement of houses, (iv) and the availability of artificial refuges and domestic animals in the peridomicile, on house invasion by triatomines. We report the occurrence of seven species of triatomines invading rural houses in the study area -T. infestans, T. guasayana, T. garciabesi, T. platensis, T. delpontei, T. breyeri and P. guentheri-. Study data suggest that invasion by triatomines occurs with higher frequency in disturbed landscapes, with houses spatially isolated and in proximity to subdivided fragments of forest. The availability of domestic refuges in the peridomestic structures as well as the presence of a higher number of domestic animals increase the chances of invasion by triatomines.
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Affiliation(s)
- Miriam Cardozo
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Cátedra de Introducción a la Biología, Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT-CONICET), Córdoba, Argentina
| | - Federico Gastón Fiad
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Cátedra de Introducción a la Biología, Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT-CONICET), Córdoba, Argentina
| | - Liliana Beatríz Crocco
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Cátedra de Introducción a la Biología, Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT-CONICET), Córdoba, Argentina
| | - David Eladio Gorla
- Universidad Nacional de Córdoba, Grupo de Ecología y Control de Vectores, Instituto de Diversidad y Ecología Animal (IDEA- CONICET), Córdoba, Argentina
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9
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Vilaseca C, Méndez MA, Pinto CF, Lemic D, Benítez HA. Unraveling the Morphological Variation of Triatoma infestans in the Peridomestic Habitats of Chuquisaca Bolivia: A Geometric Morphometric Approach. INSECTS 2021; 12:insects12020185. [PMID: 33671621 PMCID: PMC7926573 DOI: 10.3390/insects12020185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/27/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022]
Abstract
Morphometrics has been used on Triatomines, a well-known phenotypically variable insect, to understand the process of morphological plasticity and infer the changes of this phenomenon. The following research was carried out in two regions of the inter-Andean valleys and two Chaco regions of Chuquisaca-Bolivia. Triatoma infestans adults were collected from the peridomestic (pens and chicken coops) along a geographic gradient in order to evaluate the morphological differentiation between groups and their pattern of sexual shape dimorphism. Geometric morphometric methods were applied on the wings and heads of T. infestans. The main findings include that we proved sexual dimorphism in heads and wings, determined the impact of environmental factors on size and shape and validated the impact of nutrition on head shape variation. These results show that geometric morphometric procedures can be used to provide key insight into the biological adaptation of T. infestans on different biotic (nutrition) and abiotic (environment) conditions, which could serve in understanding and evaluating infestation processes and further vector control programs.
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Affiliation(s)
- Carolina Vilaseca
- Laboratorio de Ecología Química, Universidad Mayor Real y Pontificia San Francisco Xavier de Chuquisaca, Sucre, Bolivia; (C.V.); (C.F.P.)
| | - Marco A. Méndez
- Laboratorio de Genética y Evolución, Facultad de Ciencias, Instituto de Ecología y Biodiversidad, Universidad de Chile, Santiago 6640022, Chile;
| | - Carlos F. Pinto
- Laboratorio de Ecología Química, Universidad Mayor Real y Pontificia San Francisco Xavier de Chuquisaca, Sucre, Bolivia; (C.V.); (C.F.P.)
| | - Darija Lemic
- Department of Agricultural Zoology, Faculty of Agriculture, University of Zagreb, Svetošimunska 25, 10000 Zagreb, Croatia;
| | - Hugo A. Benítez
- Laboratorio de Ecología y Morfometría Evolutiva, Centro de Investigación de Estudios Avanzados del Maule, Universidad Católica del Maule, Talca 3466706, Chile
- Correspondence:
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10
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Insights into the evolution and dispersion of pyrethroid resistance among sylvatic Andean Triatoma infestans from Bolivia. INFECTION GENETICS AND EVOLUTION 2021; 90:104759. [PMID: 33556557 DOI: 10.1016/j.meegid.2021.104759] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 01/29/2021] [Accepted: 02/03/2021] [Indexed: 11/22/2022]
Abstract
Sylvatic populations of Triatoma infestans represent a challenge to Chagas disease control as they are not targeted by vector control activities and may play a key role in post-spraying house re-infestation. Understanding sylvatic foci distribution and gene flow between sylvatic and domestic populations is crucial to optimize vector control interventions and elucidate the development and spread of insecticide resistance. Herein, the genetic profiles of five Andean T. infestans populations from Bolivia with distinct insecticide susceptibility profiles were compared. Multilocus genotypes based on eight microsatellites and the DNA sequence of a fragment of the cytochrome B (cytB) gene were obtained for 92 individuals. CytB haplotypes were analyzed with previously reported Bolivian T. infestans haplotypes to evaluate putative historical gene flow among populations. Each specimen was also screened for two nucleotide mutations in the sodium channel gene (kdr), related to pyrethroid resistance (L1014 and L9251). Significant genetic differentiation was observed among all populations, although individuals of admixed origin were detected in four of them. Notably, the genetic profiles of adjacent domestic and sylvatic populations of Mataral, characterized by higher levels of insecticide resistance, support their common ancestry. Only one sylvatic individual from Mataral carried the kdr mutation L1014, suggesting that this mechanism is unlikely to cause the altered insecticide susceptibility observed in these populations. However, as the resistance mutation is present in the area, it has the potential to be selected under insecticidal pressure. Genetic comparisons of these populations suggest that insecticide resistance is likely conferred by ancient trait(s) in T. infestans sylvatic populations, which are capable of invading domiciles. These results emphasize the need for stronger entomological surveillance in the region, including early detection of house invasion, particularly post-spraying, monitoring for resistance to pyrethroids and the design of integrative control actions that consider sylvatic foci around domestic settings and their dispersion dynamics.
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11
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Clavijo-Baquet S, Cavieres G, González A, Cattan PE, Bozinovic F. Thermal performance of the Chagas disease vector, Triatoma infestans, under thermal variability. PLoS Negl Trop Dis 2021; 15:e0009148. [PMID: 33571203 PMCID: PMC7904210 DOI: 10.1371/journal.pntd.0009148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/24/2021] [Accepted: 01/14/2021] [Indexed: 11/18/2022] Open
Abstract
Vector-borne diseases (VBD) are particularly susceptible to climate change because most of the diseases' vectors are ectotherms, which themselves are susceptible to thermal changes. The Chagas disease is one neglected tropical disease caused by the protozoan parasite, Trypanosoma cruzi. One of the main vectors of the Chagas disease in South America is Triatoma infestans, a species traditionally considered to be restricted to domestic or peridomestic habitats, but sylvatic foci have also been described along its distribution. The infestation of wild individuals, together with the projections of environmental changes due to global warming, urge the need to understand the relationship between temperature and the vector's performance. Here, we evaluated the impact of temperature variability on the thermal response of T. infestans. We acclimated individuals to six thermal treatments for five weeks to then estimate their thermal performance curves (TPCs) by measuring the walking speed of the individuals. We found that the TPCs varied with thermal acclimation and body mass. Individuals acclimated to a low and variable ambient temperature (18°C ± 5°C) exhibited lower performances than those individuals acclimated to an optimal temperature (27°C ± 0°C); while those individuals acclimated to a low but constant temperature (18°C ± 0°C) did not differ in their maximal performance from those at an optimal temperature. Additionally, thermal variability (i.e., ± 5°C) at a high temperature (30°C) increased performance. These results evidenced the plastic response of T. infestans to thermal acclimation. This plastic response and the non-linear effect of thermal variability on the performance of T. infestans posit challenges when predicting changes in the vector's distribution range under climate change.
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Affiliation(s)
- Sabrina Clavijo-Baquet
- Laboratorio de Etología, Ecología y Evolución, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Grisel Cavieres
- Departamento de Ecología, Center of Applied Ecology & Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Avia González
- Departamento de Ecología, Center of Applied Ecology & Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Pedro E. Cattan
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Francisco Bozinovic
- Departamento de Ecología, Center of Applied Ecology & Sustainability (CAPES), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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12
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Gumiel M, de Mattos DP, Vieira CS, Moraes CS, Moreira CJDC, Gonzalez MS, Teixeira-Ferreira A, Waghabi M, Azambuja P, Carels N. Proteome of the Triatomine Digestive Tract: From Catalytic to Immune Pathways; Focusing on Annexin Expression. Front Mol Biosci 2020; 7:589435. [PMID: 33363206 PMCID: PMC7755933 DOI: 10.3389/fmolb.2020.589435] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/21/2020] [Indexed: 12/15/2022] Open
Abstract
Rhodnius prolixus, Panstrongylus megistus, Triatoma infestans, and Dipetalogaster maxima are all triatomines and potential vectors of the protozoan Trypanosoma cruzi responsible for human Chagas' disease. Considering that the T. cruzi's cycle occurs inside the triatomine digestive tract (TDT), the analysis of the TDT protein profile is an essential step to understand TDT physiology during T. cruzi infection. To characterize the protein profile of TDT of D. maxima, P. megistus, R. prolixus, and T. infestans, a shotgun liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach was applied in this report. Most proteins were found to be closely related to metabolic pathways such as gluconeogenesis/glycolysis, citrate cycle, fatty acid metabolism, oxidative phosphorylation, but also to the immune system. We annotated this new proteome contribution gathering it with those previously published in accordance with Gene Ontology and KEGG. Enzymes were classified in terms of class, acceptor, and function, while the proteins from the immune system were annotated by reference to the pathways of humoral response, cell cycle regulation, Toll, IMD, JNK, Jak-STAT, and MAPK, as available from the Insect Innate Immunity Database (IIID). These pathways were further subclassified in recognition, signaling, response, coagulation, melanization and none. Finally, phylogenetic affinities and gene expression of annexins were investigated for understanding their role in the protection and homeostasis of intestinal epithelial cells against the inflammation.
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Affiliation(s)
- Marcia Gumiel
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
- Research Department, Universidad Privada Franz Tamayo (UNIFRANZ), La Paz, Bolivia
| | - Debora Passos de Mattos
- Laboratório de Biologia de Insetos, Departamento de Biologia Geral, Universidade Federal Fluminense, Niterói, Brazil
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
| | - Cecília Stahl Vieira
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
- Departamento de Entomologia Molecular, Instituto Nacional de Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
| | - Caroline Silva Moraes
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Marcelo Salabert Gonzalez
- Laboratório de Biologia de Insetos, Departamento de Biologia Geral, Universidade Federal Fluminense, Niterói, Brazil
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
- Departamento de Entomologia Molecular, Instituto Nacional de Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
| | | | - Mariana Waghabi
- Laboratório de Genômica Funcional e Bioinformática, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Patricia Azambuja
- Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC/FIOCRUZ), Rio de Janeiro, Brazil
- Laboratório de Biologia de Insetos, Departamento de Biologia Geral, Universidade Federal Fluminense, Niterói, Brazil
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia, Universidade Federal Fluminense, Niterói, Brazil
- Departamento de Entomologia Molecular, Instituto Nacional de Entomologia Molecular (INCT-EM), Rio de Janeiro, Brazil
| | - Nicolas Carels
- Laboratório de Modelagem de Sistemas Biológicos, National Institute for Science and Technology on Innovation in Neglected Diseases (INCT-IDN), Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
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13
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Assessment of Shape Variation Patterns in Triatoma infestans (Klug 1834) (Hemiptera: Reduviidae: Triatominae): A First Report in Populations from Bolivia. INSECTS 2020; 11:insects11050274. [PMID: 32365855 PMCID: PMC7290822 DOI: 10.3390/insects11050274] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/27/2020] [Accepted: 04/27/2020] [Indexed: 11/18/2022]
Abstract
The morphological variations of four populations of geographically isolated Triatoma infestans located in the area of inter-Andean valleys and Chaco of Chuquisaca, Bolivia, were evaluated. Fifty-three females and sixty-one males were collected in the peri-domicile and analyzed with geometric morphometrics tools to study the patterns of the head and wing shape variation. The principal component analysis and canonical variate analysis revealed morphological variations between the populations studied, which were then confirmed by the permutation test of the differences between populations using Mahalanobis and Procustes distances. The multivariate regression analysis shows that the centroid size influences the shape of the heads and wings. T. infestans of the inter-Andean valleys are longer in the head and wings compared to the population of the Chaco. We propose that the geometric shape variation may be explained by geographical changes in climatic conditions, peri-domiciliar habitats, food source quality, and the use of insecticides.
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Enriquez GF, Cecere MC, Alvarado-Otegui JA, Alvedro A, Gaspe MS, Laiño MA, Gürtler RE, Cardinal MV. Improved detection of house infestations with triatomines using sticky traps: a paired-comparison trial in the Argentine Chaco. Parasit Vectors 2020; 13:26. [PMID: 31937361 PMCID: PMC6961371 DOI: 10.1186/s13071-020-3891-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 01/04/2020] [Indexed: 11/16/2022] Open
Abstract
Background We conducted a matched-pairs trial of three methods for detecting house infestation with triatominae bugs in a well-defined endemic rural area in the Argentine Chaco. Methods The three methods included a simple double-sided adhesive tape (ST) installed near host resting sites; timed-manual collections with a dislodging aerosol (TMC, the reference method used by vector control programmes), and householders’ bug notifications (HN). Triatomine infestations were evaluated in 103 sites of 54 houses, including domiciles, kitchens and storerooms. Results In domiciles where Triatoma infestans was collected, sensitivity of each single method decreased from 79% by ST and 77% by HN, to 57% by TMC, and increased to 92% when ST was combined with HN. In peridomestic kitchens and storerooms, TMC was relatively as sensitive as ST and significantly more sensitive than HN. On average, the number of bugs recovered by ST was 0.94 times that collected by TMC. The ST mainly collected early-instar nymphs whereas TMC yielded late (larger) stages. Triatomines caught by ST had significantly lower mean weight-to-length ratios and lower blood-feeding rates than those caught by TMC, suggesting the ST intercepted and trapped vectors seeking a blood meal host. Conclusions The ST may effectively replace TMC for detecting T. infestans in domiciles, and is especially apt for early detection of low-density domestic infestations in the frame of community-based surveillance or elimination programmes; decision making on whether an area should be targeted for full-coverage insecticide spraying, and to corroborate that extant conditions are compatible with the interruption of vector-borne transmission.![]()
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Affiliation(s)
- Gustavo Fabián Enriquez
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución (IEGEBA), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina.
| | - María Carla Cecere
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución (IEGEBA), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Julián Antonio Alvarado-Otegui
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alejandra Alvedro
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución (IEGEBA), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - María Sol Gaspe
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución (IEGEBA), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Mariano Alberto Laiño
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución (IEGEBA), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Ricardo Esteban Gürtler
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución (IEGEBA), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Marta Victoria Cardinal
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución (IEGEBA), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
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15
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Alonso-Vega C, Losada-Galván I, Pinazo MJ, Sancho Mas J, Brustenga JG, Alonso-Padilla J. The senseless orphanage of Chagas disease. Expert Opin Orphan Drugs 2019. [DOI: 10.1080/21678707.2019.1701432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
| | | | | | - Javier Sancho Mas
- ISGlobal - Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
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16
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Fernández CJ, González-Ittig RE, García BA. Genetic structure of the Chagas disease vector Triatoma infestans (Hemiptera: Reduviidae) based on nuclear and mitochondrial DNA sequences. Zool J Linn Soc 2019. [DOI: 10.1093/zoolinnean/zlz103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractIn the present study, we analysed the genetic structure of Triatoma infestans populations with a phylogeographical approach using sequences of the mitochondrial NADH dehydrogenase subunit 5 (ND5) and the nuclear elongation factor-1 alpha (EF-1α) genes of bugs obtained from Argentina and Bolivia. Spatially circumscribed haplogroups were distinguished from the ND5 gene sequences, one distributed exclusively to the south of the studied area and, in agreement with the results from the EF-1α gene, one haplogroup limited to Bolivia and another to Morajú located in the Chaco region of Argentina. In both the ND5 and EF-1α networks, the most widespread haplogroup or allele group showed a star-like topology, which is compatible with a recent demographic expansion. The asymmetric historical gene flow detected from a population of the Chaco region towards Bolivia and the spatiotemporal phylogeographical reconstruction of lineage dispersal would support the hypothesis that postulates the Chaco biogeographical region as the area of origin for the species. However, additional studies with a broader sampling in the Andean region are needed to define with certainty whether the origin of T. infestans is Chacoan or Andean.
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Affiliation(s)
- Cintia J Fernández
- Instituto de Investigaciones en Ciencias de la Salud (INICSA), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba (CONICET-UNC), Córdoba, Argentina
- Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Raúl E González-Ittig
- Instituto de Diversidad y Ecología Animal (IDEA), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba (CONICET-UNC), Córdoba, Argentina
- Cátedra de Genética de Poblaciones y Evolución, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Beatriz A García
- Instituto de Investigaciones en Ciencias de la Salud (INICSA), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba (CONICET-UNC), Córdoba, Argentina
- Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Monteiro FA, Weirauch C, Felix M, Lazoski C, Abad-Franch F. Evolution, Systematics, and Biogeography of the Triatominae, Vectors of Chagas Disease. ADVANCES IN PARASITOLOGY 2019. [PMID: 29530308 DOI: 10.1016/bs.apar.2017.12.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In this chapter, we review and update current knowledge about the evolution, systematics, and biogeography of the Triatominae (Hemiptera: Reduviidae)-true bugs that feed primarily on vertebrate blood. In the Americas, triatomines are the vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Despite declining incidence and prevalence, Chagas disease is still a major public health concern in Latin America. Triatomines occur also in the Old World, where vector-borne T. cruzi transmission has not been recorded. Triatomines evolved from predatory reduviid bugs, most likely in the New World, and diversified extensively across the Americas (including the Caribbean) and in parts of Asia and Oceania. Here, we first discuss our current understanding of how, how many times, and when the blood-feeding habit might have evolved among the Reduviidae. Then we present a summary of recent advances in the systematics of this diverse group of insects, with an emphasis on the contribution of molecular tools to the clarification of taxonomic controversies. Finally, and in the light of both up-to-date phylogenetic hypotheses and a thorough review of distribution records, we propose a global synthesis of the biogeography of the Triatominae. Over 130 triatomine species contribute to maintaining T. cruzi transmission among mammals (sometimes including humans) in almost every terrestrial ecoregion of the Americas. This means that Chagas disease will never be eradicated and underscores the fact that effective disease prevention will perforce require stronger, long-term vector control-surveillance systems.
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Affiliation(s)
- Fernando Araujo Monteiro
- Laboratório de Epidemiologia e Sistemática Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil.
| | | | - Márcio Felix
- Laboratório de Biodiversidade Entomológica, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil
| | - Cristiano Lazoski
- Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Brenière SF, Buitrago R, Waleckx E, Depickère S, Sosa V, Barnabé C, Gorla D. Wild populations of Triatoma infestans: Compilation of positive sites and comparison of their ecological niche with domestic population niche. Acta Trop 2017; 176:228-235. [PMID: 28818626 DOI: 10.1016/j.actatropica.2017.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 07/26/2017] [Accepted: 08/10/2017] [Indexed: 11/15/2022]
Abstract
BACKGROUND For several years, the wild populations of Triatoma infestans, main vector of Trypanosoma cruzi causing Chagas disease, have been considered or suspected of being a source of reinfestation of villages. The number of sites reported for the presence of wild T. infestans, often close to human habitats, has greatly increased, but these data are scattered in several publications, and others obtained by our team in Bolivia have not been published yet. METHODOLOGY/PRINCIPAL FINDINGS Herein is compiled the largest number of wild sites explored for the presence of T. infestans collected with two methods The standardized methods aimed to determine the relationship between wild T. infestans and the ecoregion, and the directed method help to confirm the presence/absence of triatomines in the ecoregions. Entomological indices were compared between ecoregions and an environmental niche modelling approach, based on bioclimatic variables, was applied. The active search for wild T. infestans in Bolivia suggests a discontinuous distribution from the Andean valleys to the lowlands (Chaco), while the models used suggest a continuous distribution between the two regions and very large areas where wild populations remain to be discovered. The results compile the description of different habitats where these populations were found, and we demonstrate that the environmental niches of wild and domestic populations, defined by climatic variables, are similar but not equivalent, showing that during domestication, T. infestans has conquered new spaces with wider ranges of temperature and precipitation. CONCLUSIONS/SIGNIFICANCE The great diversity of wild T. infestans habitats and the comparison of their ecological niches with that of domestic populations confirm the behavioural plasticity of the species that increase the possibility of contact with humans. The result of the geographical distribution model of the wild populations calls for more entomological vigilance in the corresponding areas in the Southern Cone countries and in Bolivia. The current presentation is the most comprehensive inventory of wild T. infestans-positive sites that can be used as a reference for further entomological vigilance in inhabited areas.
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Affiliation(s)
- Simone Frédérique Brenière
- INTERTRYP, CIRAD, IRD, TA A-17/G, International Campus in Baillarguet, Montpellier, France; Centro de Investigación para la Salud en América Latina (CISeAL), Pontificia Universidad Católica del Ecuador (PUCE), Av. 12 de Octubre 1076 y Roca, Campus Nayón, Quito, Ecuador.
| | - Rosio Buitrago
- INTERTRYP, CIRAD, IRD, TA A-17/G, International Campus in Baillarguet, Montpellier, France; Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, Rafael Zubieta #1889, Miraflores, Casilla M-10019, La Paz, Bolivia
| | - Etienne Waleckx
- Laboratorio de Parasitología, Centro de Investigaciones Regionales "Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Stéphanie Depickère
- INTERTRYP, CIRAD, IRD, TA A-17/G, International Campus in Baillarguet, Montpellier, France; Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, Rafael Zubieta #1889, Miraflores, Casilla M-10019, La Paz, Bolivia; Grupo de Sistemas Complejos, Instituto de Investigaciones Físicas, Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Victor Sosa
- INTERTRYP, CIRAD, IRD, TA A-17/G, International Campus in Baillarguet, Montpellier, France; Dirección de Recursos Naturales, Secretaria de Desarrollo Sostenible y Medio Ambiente, Gobierno Autónomo Departamental de Santa Cruz, Av. Fransisco Mora 3er Anillo interno, Zona Polanco, Mexico
| | - Christian Barnabé
- INTERTRYP, CIRAD, IRD, TA A-17/G, International Campus in Baillarguet, Montpellier, France
| | - David Gorla
- Instituto Altos Estudios Espaciales Mario Gulich, Universidad Nacional Córdoba-CONAE, Ruta C45 Km 8, Falda del Cañete, 5187 Córdoba, Argentina
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19
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de Arias AR, Carbajal de la Fuente AL, Gómez A, Cecere MC, Rolón M, Gómez MCV, Villalba C. Morphometric Wings Similarity among Sylvatic and Domestic Populations of Triatoma infestans (Hemiptera: Reduviidae) from the Gran Chaco Region of Paraguay. Am J Trop Med Hyg 2017; 97:481-488. [PMID: 28829725 PMCID: PMC5544089 DOI: 10.4269/ajtmh.16-1013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/14/2017] [Indexed: 12/03/2022] Open
Abstract
Despite sustained efforts for eliminating Triatoma infestans, reinfestation still persists in large part of the endemic area of Chagas disease from the Gran Chaco region. Sylvatic T. infestans populations seem to threat success of control programs of domestic T. infestans. In this study, we analyze whether T. infestans collected after a community-wide spraying were survivors or were immigrants from elsewhere using geometric morphometric tools. We used 101 right wings of female T. infestans captured before and after intervention program carried out in 12 de Junio and Casuarina, villages from Paraguayan Chaco, and in Puerto Casado during presprayed collection. There were no significant differences in wing size of domestic T. infestans between pre- and postspraying populations, and between domestic and sylvatic ones. When shape variables originating from postintervention individuals from 12 de Junio were introduced one by one into a discriminant analysis, the greatest weight (53%) was allocated to the sylvatic group. Furthermore, from the prespraying population, 25% were reallocated as postintervention individuals. Only 11% of the insects were reassigned to other groups Puerto Casado and Casuarina. These results suggest that postspraying individuals appear to have different origins. Half of the postspraying individuals from 12 de Junio were similar to the sylvatic ones and 25% of these were similar to those captured in the prespraying period. This remarkable morphometric wings similarity between sylvatic and domestic populations is new evidence suggesting that they could be highly related to each other in the Paraguayan Chaco; human-fed bugs from sylvatic area also support this.
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Affiliation(s)
- Antonieta Rojas de Arias
- Centro para el Desarrollo de la Investigación Científica (CEDIC), Diaz Gill Medicina Laboratorial/Fundación Moisés Bertoni, Asunción, Paraguay
| | - Ana Laura Carbajal de la Fuente
- Laboratorio de Eco-Epidemiología, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Ana Gómez
- Centro para el Desarrollo de la Investigación Científica (CEDIC), Diaz Gill Medicina Laboratorial/Fundación Moisés Bertoni, Asunción, Paraguay
| | - María Carla Cecere
- Laboratorio de Eco-Epidemiología, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales (FCEyN), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - Miriam Rolón
- Centro para el Desarrollo de la Investigación Científica (CEDIC), Diaz Gill Medicina Laboratorial/Fundación Moisés Bertoni, Asunción, Paraguay
| | - María Celeste Vega Gómez
- Centro para el Desarrollo de la Investigación Científica (CEDIC), Diaz Gill Medicina Laboratorial/Fundación Moisés Bertoni, Asunción, Paraguay
| | - Cesia Villalba
- Programa Nacional de Control de la Enfermedad de Chagas, SENEPA, Asunción, Paraguay
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20
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Hernandez-Castro LE, Paterno M, Villacís AG, Andersson B, Costales JA, De Noia M, Ocaña-Mayorga S, Yumiseva CA, Grijalva MJ, Llewellyn MS. 2b-RAD genotyping for population genomic studies of Chagas disease vectors: Rhodnius ecuadoriensis in Ecuador. PLoS Negl Trop Dis 2017; 11:e0005710. [PMID: 28723901 PMCID: PMC5536387 DOI: 10.1371/journal.pntd.0005710] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 07/31/2017] [Accepted: 06/13/2017] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Rhodnius ecuadoriensis is the main triatomine vector of Chagas disease, American trypanosomiasis, in Southern Ecuador and Northern Peru. Genomic approaches and next generation sequencing technologies have become powerful tools for investigating population diversity and structure which is a key consideration for vector control. Here we assess the effectiveness of three different 2b restriction site-associated DNA (2b-RAD) genotyping strategies in R. ecuadoriensis to provide sufficient genomic resolution to tease apart microevolutionary processes and undertake some pilot population genomic analyses. METHODOLOGY/PRINCIPAL FINDINGS The 2b-RAD protocol was carried out in-house at a non-specialized laboratory using 20 R. ecuadoriensis adults collected from the central coast and southern Andean region of Ecuador, from June 2006 to July 2013. 2b-RAD sequencing data was performed on an Illumina MiSeq instrument and analyzed with the STACKS de novo pipeline for loci assembly and Single Nucleotide Polymorphism (SNP) discovery. Preliminary population genomic analyses (global AMOVA and Bayesian clustering) were implemented. Our results showed that the 2b-RAD genotyping protocol is effective for R. ecuadoriensis and likely for other triatomine species. However, only BcgI and CspCI restriction enzymes provided a number of markers suitable for population genomic analysis at the read depth we generated. Our preliminary genomic analyses detected a signal of genetic structuring across the study area. CONCLUSIONS/SIGNIFICANCE Our findings suggest that 2b-RAD genotyping is both a cost effective and methodologically simple approach for generating high resolution genomic data for Chagas disease vectors with the power to distinguish between different vector populations at epidemiologically relevant scales. As such, 2b-RAD represents a powerful tool in the hands of medical entomologists with limited access to specialized molecular biological equipment.
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Affiliation(s)
- Luis E. Hernandez-Castro
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Marta Paterno
- Department of Biology, University of Padua, Padua, Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Rome, Italy
| | - Anita G. Villacís
- Center for Research on Health in Latin America, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
| | - Björn Andersson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jaime A. Costales
- Center for Research on Health in Latin America, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
| | - Michele De Noia
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany
| | - Sofía Ocaña-Mayorga
- Center for Research on Health in Latin America, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
| | - Cesar A. Yumiseva
- Center for Research on Health in Latin America, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
| | - Mario J. Grijalva
- Center for Research on Health in Latin America, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
- Infectious and Tropical Disease Institute, Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Ohio, United States of America
| | - Martin S. Llewellyn
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
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21
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Provecho YM, Gaspe MS, Fernández MDP, Gürtler RE. House Reinfestation With Triatoma infestans (Hemiptera: Reduviidae) After Community-Wide Spraying With Insecticides in the Argentine Chaco: A Multifactorial Process. JOURNAL OF MEDICAL ENTOMOLOGY 2017; 54:646-657. [PMID: 28399199 DOI: 10.1093/jme/tjw224] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 11/29/2016] [Indexed: 06/07/2023]
Abstract
We investigated the dynamics and underlying causes of house (re)infestation with Triatoma infestans (Klug 1834) after a community-wide residual spraying with pyrethroids in a well-defined rural section of Pampa del Indio municipality (northeastern Argentina) over a 4-yr period. House infestation was assessed by timed manual searches, during insecticide applications, and by opportunistic householders' bug collections. All reinfested houses were selectively re-sprayed with insecticides. The resident population comprised Qom (66.6%) and Creole (33.4%) households, whose sociodemographic profiles differed substantially. The prevalence of house infestation dropped, less than expected, from 20.5% at baseline to 5.0% at 14 months postspraying (MPS), and then fluctuated between 0.8 and 4.2% over 21-51 MPS. Postspraying house infestation was positively and highly significantly associated with prespraying infestation. Most of the foci detected over 14-21 MPS were considered persistent (residual), some of which were moderately resistant to pyrethroids and were suppressed with malathion. Infestation patterns over 27-51 MPS suggested bug invasion from internal or external foci, but the sources of most findings were unaccounted for. Local spatial analysis identified two hotspots of postspraying house infestation. Using multimodel inference with model averaging, we corroborated that baseline domestic infestation was closely related to refuge availability, housing quality, and occurrence of peridomestic infestation. The diminished effectiveness of single pyrethroid treatments, partly attributable to moderate resistance compounded with rather insensitive vector detection methods and poor housing conditions, contributed to vector persistence. Improved control strategies combined with broad social participation are needed for the sustainable elimination of vector-borne human Chagas disease from the Gran Chaco.
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Affiliation(s)
- Yael M Provecho
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina (; ; ; )
| | - M Sol Gaspe
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina (; ; ; )
| | - M Del Pilar Fernández
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina (; ; ; )
| | - Ricardo E Gürtler
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina (; ; ; )
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22
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Carbajal-de-la-Fuente AL, Lencina P, Spillmann C, Gürtler RE. A motorized vehicle-mounted sprayer as a new tool for Chagas disease vector control. CAD SAUDE PUBLICA 2017; 33:e00099115. [DOI: 10.1590/0102-311x00099115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 01/21/2016] [Indexed: 11/21/2022] Open
Abstract
Abstract: Residual insecticide spraying still is the main tool used to suppress house infestations with Chagas disease vectors. While manual compression sprayers (MCS) have traditionally been used in Latin America, Mendoza's vector control program from Argentina introduced the use of a modified motorized vehicle-mounted sprayer (VMS) with apparent advantages over MCS. We conducted a randomized intervention trial to evaluate the effectiveness and selected components of the performance of MCS and VMS. We assessed house infestation by Triatoma infestans in 76 previously-infested houses at 0, 1, 4 and 12 months postintervention. Infestations were reduced substantially, with no significant differences between treatments. End-point infestations were restricted to peridomiciles. Although VMS required less time to complete the house spraying than MCS, both treatments had similar performance and did not suppress infestations completely. The main relative advantages of VMS were a reduced physical effort, especially under harsh field conditions, and potential gains in spray coverage per unit of time.
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23
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Durán P, Siñani E, Depickère S. On triatomines, cockroaches and haemolymphagy under laboratory conditions: new discoveries. Mem Inst Oswaldo Cruz 2016; 111:605-613. [PMID: 27706376 PMCID: PMC5066326 DOI: 10.1590/0074-02760160027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 07/19/2016] [Indexed: 11/22/2022] Open
Abstract
For a long time, haematophagy was considered an obligate condition for triatomines
(Hemiptera: Reduviidae) to complete their life cycle. Today, the ability to use
haemolymphagy is suggested to represent an important survival strategy for some
species, especially those in genus Belminus. As Eratyrus
mucronatus and Triatoma boliviana are found with
cockroaches in the Blaberinae subfamily in Bolivia, their developmental cycle from
egg to adult under a “cockroach diet” was studied. The results suggested that having
only cockroach haemolymph as a food source compromised development cycle completion
in both species. Compared to a “mouse diet”, the cockroach diet increased: (i) the
mortality at each nymphal instar; (ii) the number of feedings needed to molt; (iii)
the volume of the maximum food intake; and (iv) the time needed to molt. In
conclusion, haemolymph could effectively support survival in the field in both
species. Nevertheless, under laboratory conditions, the use of haemolymphagy as a
survival strategy in the first developmental stages of these species was not
supported, as their mortality was very high. Finally, when Triatoma
infestans, Rhodnius stali and Panstrongylus
rufotuberculatus species were reared on a cockroach diet under similar
conditions, all died rather than feeding on cockroaches. These results are discussed
in the context of the ecology of each species.
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Affiliation(s)
- Pamela Durán
- Universidad Mayor de San Andrés, Instituto de Investigación en Salud y Desarrollo, Cátedra de Parasitología, La Paz, Bolivia
| | - Edda Siñani
- Instituto Nacional de Laboratorios de Salud, Laboratorio de Entomología Médica, La Paz, Bolivia
| | - Stéphanie Depickère
- Instituto Nacional de Laboratorios de Salud, Laboratorio de Entomología Médica, La Paz, Bolivia.,Institut de Recherche pour le Développement, Embajada Francia, La Paz, Plurinational State of Bolivia
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24
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Morris E, Bone C. Identifying spatial data availability and spatial data needs for Chagas disease mitigation in South America. Spat Spatiotemporal Epidemiol 2016; 17:45-58. [DOI: 10.1016/j.sste.2016.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 02/04/2016] [Accepted: 04/12/2016] [Indexed: 11/16/2022]
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25
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Messenger LA, Garcia L, Vanhove M, Huaranca C, Bustamante M, Torrico M, Torrico F, Miles MA, Llewellyn MS. Ecological host fitting of Trypanosoma cruzi TcI in Bolivia: mosaic population structure, hybridization and a role for humans in Andean parasite dispersal. Mol Ecol 2015; 24:2406-22. [PMID: 25847086 PMCID: PMC4737126 DOI: 10.1111/mec.13186] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 03/02/2015] [Accepted: 03/13/2015] [Indexed: 01/04/2023]
Abstract
An improved understanding of how a parasite species exploits its genetic repertoire to colonize novel hosts and environmental niches is crucial to establish the epidemiological risk associated with emergent pathogenic genotypes. Trypanosoma cruzi, a genetically heterogeneous, multi-host zoonosis, provides an ideal system to examine the sylvatic diversification of parasitic protozoa. In Bolivia, T. cruzi I, the oldest and most widespread genetic lineage, is pervasive across a range of ecological clines. High-resolution nuclear (26 loci) and mitochondrial (10 loci) genotyping of 199 contemporaneous sylvatic TcI clones was undertaken to provide insights into the biogeographical basis of T. cruzi evolution. Three distinct sylvatic parasite transmission cycles were identified: one highland population among terrestrial rodent and triatomine species, composed of genetically homogenous strains (Ar = 2.95; PA/L = 0.61; DAS = 0.151), and two highly diverse, parasite assemblages circulating among predominantly arboreal mammals and vectors in the lowlands (Ar = 3.40 and 3.93; PA/L = 1.12 and 0.60; DAS = 0.425 and 0.311, respectively). Very limited gene flow between neighbouring terrestrial highland and arboreal lowland areas (distance ~220 km; FST = 0.42 and 0.35) but strong connectivity between ecologically similar but geographically disparate terrestrial highland ecotopes (distance >465 km; FST = 0.016-0.084) strongly supports ecological host fitting as the predominant mechanism of parasite diversification. Dissimilar heterozygosity estimates (excess in highlands, deficit in lowlands) and mitochondrial introgression among lowland strains may indicate fundamental differences in mating strategies between populations. Finally, accelerated parasite dissemination between densely populated, highland areas, compared to uninhabited lowland foci, likely reflects passive, long-range anthroponotic dispersal. The impact of humans on the risk of epizootic Chagas disease transmission in Bolivia is discussed.
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Affiliation(s)
- Louisa A. Messenger
- Department of Pathogen Molecular BiologyFaculty of Infectious and Tropical DiseasesLondon School of Hygiene and Tropical MedicineLondonUK
| | - Lineth Garcia
- Institute of Biomedical ResearchUniversidad Mayor de San SimónCochabambaBolivia
| | - Mathieu Vanhove
- Department of Infectious Disease EpidemiologyImperial College LondonLondonUK
| | - Carlos Huaranca
- Institute of Biomedical ResearchUniversidad Mayor de San SimónCochabambaBolivia
| | - Marinely Bustamante
- Institute of Biomedical ResearchUniversidad Mayor de San SimónCochabambaBolivia
| | - Marycruz Torrico
- Institute of Biomedical ResearchUniversidad Mayor de San SimónCochabambaBolivia
| | - Faustino Torrico
- Institute of Biomedical ResearchUniversidad Mayor de San SimónCochabambaBolivia
| | - Michael A. Miles
- Department of Pathogen Molecular BiologyFaculty of Infectious and Tropical DiseasesLondon School of Hygiene and Tropical MedicineLondonUK
| | - Martin S. Llewellyn
- Department of Pathogen Molecular BiologyFaculty of Infectious and Tropical DiseasesLondon School of Hygiene and Tropical MedicineLondonUK
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26
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Waleckx E, Gourbière S, Dumonteil E. Intrusive versus domiciliated triatomines and the challenge of adapting vector control practices against Chagas disease. Mem Inst Oswaldo Cruz 2015; 110:324-38. [PMID: 25993504 PMCID: PMC4489470 DOI: 10.1590/0074-02760140409] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 03/09/2015] [Indexed: 11/22/2022] Open
Abstract
Chagas disease prevention remains mostly based on triatomine vector control to reduce or eliminate house infestation with these bugs. The level of adaptation of triatomines to human housing is a key part of vector competence and needs to be precisely evaluated to allow for the design of effective vector control strategies. In this review, we examine how the domiciliation/intrusion level of different triatomine species/populations has been defined and measured and discuss how these concepts may be improved for a better understanding of their ecology and evolution, as well as for the design of more effective control strategies against a large variety of triatomine species. We suggest that a major limitation of current criteria for classifying triatomines into sylvatic, intrusive, domiciliary and domestic species is that these are essentially qualitative and do not rely on quantitative variables measuring population sustainability and fitness in their different habitats. However, such assessments may be derived from further analysis and modelling of field data. Such approaches can shed new light on the domiciliation process of triatomines and may represent a key tool for decision-making and the design of vector control interventions.
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Affiliation(s)
- Etienne Waleckx
- Laboratorio de Parasitología, Centro de Investigaciones Regionales Dr
Hideyo Noguchi, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Sébastien Gourbière
- Institut de Modélisation et d’Analyses en Géo-Environnement et Santé,
Université de Perpignan Via Domitia, Perpignan, France
| | - Eric Dumonteil
- Laboratorio de Parasitología, Centro de Investigaciones Regionales Dr
Hideyo Noguchi, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
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27
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Gaspe MS, Provecho YM, Piccinali RV, Gürtler RE. Where do these bugs come from? Phenotypic structure of Triatoma infestans populations after control interventions in the Argentine Chaco. Mem Inst Oswaldo Cruz 2015; 110:310-8. [PMID: 25946158 PMCID: PMC4489468 DOI: 10.1590/0074-02760140376] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 03/18/2015] [Indexed: 11/22/2022] Open
Abstract
House re-invasion by native triatomines after insecticide-based control campaigns
represents a major threat for Chagas disease vector control. We conducted a
longitudinal intervention study in a rural section (Area III, 407 houses) of Pampa
del Indio, northeastern Argentina, and used wing geometric morphometry to compare
pre-spray and post-spray (re-infestant bugs) Triatoma infestans
populations. The community-wide spraying with pyrethroids reduced the prevalence of
house infestation by T. infestans from 31.9% to < 1% during a
four-year follow-up, unlike our previous studies in the neighbouring Area I. Two
groups of bug collection sites differing in wing shape variables before interventions
(including 221 adults from 11 domiciles) were used as a reference for assigning 44
post-spray adults. Wing shape variables from post-spray, high-density bug colonies
and pre-spray groups were significantly different, suggesting that re-infestant
insects had an external origin. Insects from one house differed strongly in wing
shape variables from all other specimens. A further comparison between insects from
both areas supported the existence of independent re-infestation processes within the
same district. These results point to local heterogeneities in house re-infestation
dynamics and emphasise the need to expand the geographic coverage of vector
surveillance and control operations to the affected region.
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Affiliation(s)
- María Sol Gaspe
- Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Yael Mariana Provecho
- Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Romina Valeria Piccinali
- Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ricardo Esteban Gürtler
- Instituto de Ecología, Genética y Evolución, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
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28
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Nouvellet P, Cucunubá ZM, Gourbière S. Ecology, evolution and control of Chagas disease: a century of neglected modelling and a promising future. ADVANCES IN PARASITOLOGY 2015; 87:135-91. [PMID: 25765195 DOI: 10.1016/bs.apar.2014.12.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
More than 100 years after its formal description, Chagas disease remains a major public health concern in Latin America with a yearly burden of 430,000 Disability-Adjusted Life Years (DALYs). The aetiological agent, a protozoan named Trypanosoma cruzi, is mainly transmitted to mammalian hosts by triatomine vectors. Multiple species of mammals and triatomines can harbour and transmit the parasite, and the feeding range of triatomine species typically includes many noncompetent hosts. Furthermore, the transmission of the pathogen can occur via several routes including the typical vector's faeces, but also oral, congenital and blood transfusion routes. These ecological and epidemiological complexities of the disease have hindered many control initiatives. In such a context, mathematical models provide invaluable tools to explore and understand the dynamics of T. cruzi transmission, and to design, optimize and monitor the efficacy of control interventions. We intend here to provide the first review of the mathematical models of Chagas disease, focussing on how they have contributed to our understanding of (1) the population dynamics and control of triatomine vectors, and (2) the epidemiology of T. cruzi infections. We also aim at suggesting promising lines of modelling that could further improve our understanding of the ecology, evolution, and control of the disease.
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Affiliation(s)
- Pierre Nouvellet
- Medical Research Council Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Zulma M Cucunubá
- Grupo de Parasitología, Instituto Nacional de Salud, Colombia; Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Sébastien Gourbière
- Institut de Modélisation et d'Analyse en Géo-Environnements et Santé (IMAGES), Université de Perpignan Via Domitia, Perpignan, France
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29
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Salvatella R, Irabedra P, Castellanos LG. Interruption of vector transmission by native vectors and "the art of the possible". Mem Inst Oswaldo Cruz 2015; 109:122-5. [PMID: 24626310 PMCID: PMC4005527 DOI: 10.1590/0074-0276140338] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 09/26/2013] [Indexed: 11/22/2022] Open
Abstract
In a recent article in the Reader’s Opinion, advantages and disadvantages of the
certification processes of interrupted Chagas disease transmission (American
trypanosomiasis) by native vector were discussed. Such concept, accepted by those
authors for the case of endemic situations with introduced vectors, has been built on
a long and laborious process by endemic countries and Subregional Initiatives for
Prevention, Control and Treatment of Chagas, with Technical Secretariat of the Pan
American Health Organization/World Health Organization, to create a horizon target
and goal to concentrate priorities and resource allocation and actions. With varying
degrees of sucess, which are not replaceable for a certificate of good practice, has
allowed during 23 years to safeguard the effective control of transmission of
Trypanosoma cruzi not to hundreds of thousands, but millions of people at risk
conditions, truly “the art of the possible.”
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Affiliation(s)
- Roberto Salvatella
- Communicable Diseases and Health Analysis Department, Neglected, Tropical and Vector Borne Diseases Unit, WashingtonDC, USA, Communicable Diseases and Health Analysis Department , Neglected, Tropical and Vector Borne Diseases Unit , Washington DC , USA
| | - Pilar Irabedra
- Communicable Diseases and Health Analysis Department, Neglected, Tropical and Vector Borne Diseases Unit, WashingtonDC, USA, Communicable Diseases and Health Analysis Department , Neglected, Tropical and Vector Borne Diseases Unit , Washington DC , USA
| | - Luis G Castellanos
- Communicable Diseases and Health Analysis Department, Neglected, Tropical and Vector Borne Diseases Unit, WashingtonDC, USA, Communicable Diseases and Health Analysis Department , Neglected, Tropical and Vector Borne Diseases Unit , Washington DC , USA
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30
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Santo-Orihuela PL, Carvajal G, Picollo MI, Vassena CV. Analysing deltamethrin susceptibility and pyrethroid esterase activity variations in sylvatic and domestic Triatoma infestans at the embryonic stage. Mem Inst Oswaldo Cruz 2015; 108:1031-6. [PMID: 24402155 PMCID: PMC4005558 DOI: 10.1590/0074-0276130184] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 09/26/2013] [Indexed: 11/22/2022] Open
Abstract
The aim of the present work was to study the deltamethrin susceptibility of eggs from Triatoma infestans populations and the contribution of pyrethroid esterases to deltamethrin degradation. Insects were collected from sylvatic areas, including Veinte de Octubre and Kirus-Mayu (Bolivia) and from domiciliary areas, including El Palmar (Bolivia) and La Pista (Argentina). Deltamethrin susceptibility was determined by dose-response bioassays. Serial dilutions of deltamethrin (0.0005-1 mg/mL) were topically applied to 12-day-old eggs. Samples from El Palmar had the highest lethal dose ratio (LDR) value (44.90) compared to the susceptible reference strain (NFS), whereas the Veinte de Octubre samples had the lowest value (0.50). Pyrethroid esterases were evaluated using 7-coumaryl permethrate (7-CP) on individually homogenised eggs from each population and from NFS. The El Palmar and La Pista samples contained 40.11 and 36.64 pmol/min/mg protein, respectively, and these values were statistically similar to NFS (34.92 pmol/min/mg protein) and different from Kirus-Mayu and Veinte de Octubre (27.49 and 22.69 pmol/min/mg protein, respectively). The toxicological data indicate that the domestic populations were resistant to deltamethrin, but no statistical contribution of 7-CP esterases was observed. The sylvatic populations had similar LDR values to NFS, but lower 7-CP esterase activities. Moreover, this is the first study of the pyrethroid esterases on T. infestans eggs employing a specific substrate (7-CP).
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Gomez MB, D'Avila GCP, Orellana ALG, Cortez MR, Rosa ACL, Noireau F, Diotaiuti LG. Susceptibility to deltamethrin of wild and domestic populations of Triatoma infestans of the Gran Chaco and the Inter-Andean Valleys of Bolivia. Parasit Vectors 2014; 7:497. [PMID: 25394392 PMCID: PMC4240893 DOI: 10.1186/s13071-014-0497-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 10/21/2014] [Indexed: 11/26/2022] Open
Abstract
Background The persistence of Triatoma infestans and the continuous transmission of Trypanosoma cruzi in the Inter-Andean Valleys and in the Gran Chaco of Bolivia are of great significance. Coincidentally, it is in these regions the reach of the vector control strategies is limited, and reports of T. infestans resistance to insecticides, including in wild populations, have been issued. This study aims to characterize the susceptibility to deltamethrin of wild and domestic populations of T. infestans from Bolivia, in order to better understand the extent of this relevant problem. Methods Susceptibility to deltamethrin was assessed in nine, wild and domestic, populations of T. infestans from the Gran Chaco and the Inter-Andean Valleys of Bolivia. Serial dilutions of deltamethrin in acetone (0.2 μL) were topically applied in first instar nymphs (F1, five days old, fasting, weight 1.2 ± 0.2 mg). Dose response results were analyzed with PROBIT version 2, determining the lethal doses, slope and resistance ratios (RR). Qualitative tests were also performed. Results Three wild T. infestans dark morph samples of Chaco from the Santa Cruz Department were susceptible to deltamethrin with RR50 of <2, and 100% mortality to the diagnostic dose (DD); however, two domestic populations from the same region were less susceptible than the susceptibility reference lineage (RR50 of 4.21 and 5.04 respectively and 93% DD). The domestic population of Villa Montes from the Chaco of the Tarija Department presented high levels of resistance (RR50 of 129.12 and 0% DD). Moreover, the domestic populations from the Valleys of the Cochabamba Department presented resistance (RR50 of 8.49 and 62% DD), the wild populations were less susceptible than SRL and T. infestans dark morph populations (RR50 < 5). Conclusion The elimination of T. infestans with pyrethroid insecticides in Brazil, Uruguay, Chile, and its drastic reduction in large parts of Paraguay and Argentina, clearly indicates that pyrethroid resistance was very uncommon in non-Andean regions. The pyrethroid susceptibility of non-Andean T. infestans dark morph population, and the resistance towards it, of Andean T. infestans wild and domestic populations, indicates that the Andean populations from Bolivia are less susceptible.
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Affiliation(s)
- Marinely Bustamante Gomez
- Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou - FIOCRUZ Minas, Belo Horizonte, Brazil.
| | - Grasielle Caldas Pessoa D'Avila
- Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou - FIOCRUZ Minas, Belo Horizonte, Brazil.
| | - Ana Lineth Garcia Orellana
- Instituto de Investigaciones Biomédicas - Facultad de Medicina, Universidad Mayor de San Simón, Cochabamba, Bolivia.
| | | | - Aline Cristine Luiz Rosa
- Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou - FIOCRUZ Minas, Belo Horizonte, Brazil.
| | - François Noireau
- Institute de Recherche pour le Developemente (IRD), La Paz, Bolivia.
| | - Liléia Gonçalves Diotaiuti
- Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou - FIOCRUZ Minas, Belo Horizonte, Brazil.
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Santo-Orihuela PL, Carvajal G, Picollo MI, Vassena CV. Toxicological and biochemical analysis of the susceptibility of sylvatic Triatoma infestans from the Andean Valley of Bolivia to organophosphate insecticide. Mem Inst Oswaldo Cruz 2014; 108:790-5. [PMID: 24037203 PMCID: PMC3970684 DOI: 10.1590/0074-0276108062013017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/16/2013] [Indexed: 11/22/2022] Open
Abstract
To increase our knowledge of the natural susceptibility of Triatoma
infestans to an organophosphate insecticide, we performed
toxicological and biochemical studies on three sylvatic populations from Bolivia
and two populations from domestic dwellings from Bolivia and Argentina.
Fifty-per-cent lethal doses (LD50) were determined based on the topical
application of fenitrothion on first instar nymphs and mortality was assessed at
24 h. Both type of populations exhibited LD50ratios significantly higher than 1
with a range of the values (1.42-2.47); the maximum value were found in a
sylvatic (-S) population, Veinte de Octubre-S. Samples were biochemically
analysed using a glutathione S-transferase activity assay. The highest
significant activity was obtained for Veinte de Octubre-S and the lowest
activity was obtained for the reference population (102.69 and 54.23 pmol per
minute per mg of protein respectively). Two out of the three sylvatic
populations (Veinte de Octubre-S and Kirus Mayu-S) exhibited significantly
higher glutathione S-transferase activity than that of the reference population.
Based on this analysis of the natural susceptibility of this organism to
organophosphate insecticides, continental and focal surveys of organophosphate
susceptibility should be conducted to evaluate the evolution and distribution of
this phenomenon.
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Brémond P, Salas R, Waleckx E, Buitrago R, Aliaga C, Barnabé C, Depickère S, Dangles O, Brenière SF. Variations in time and space of an Andean wild population of T. infestans at a microgeographic scale. Parasit Vectors 2014; 7:164. [PMID: 24708673 PMCID: PMC3992151 DOI: 10.1186/1756-3305-7-164] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 03/21/2014] [Indexed: 11/13/2022] Open
Abstract
Background Wild populations of Triatoma infestans are now believed to be the source of reinfestation of dwellings in some Andean areas and could impede the full achievement of vector control campaigns in this region. Given the poor knowledge of these populations in natural conditions, their basic biology traits, such as monthly demographic variations and movements of individuals, were explored. Methods A previously identified wild population of T. infestans in a field adjacent to a group of isolated houses in an Andean valley (department of La Paz, Bolivia) was explored using regular capture assays over 13 months in 50 sites selected at the beginning of the study. The capture-mark-recapture method was applied monthly using mouse-baited adhesive traps for captures and fingernail polish of different colors for the marking. Results The monthly capture assays did not show significant differences between rainy and dry seasons, showing evidence for a certain stability of the wild T. infestans population with only the nymph population tending to decline during the middle of the rainy season when rain is more intensive. Throughout the study, the monthly average number of bugs was 51.1 ± 25.3 per assay, 91.1% were nymphs, and they were found at 30 of the 50 sites (60%). The number of times a site was positive varied from one to 13. Site infestation was associated with the underground position of the traps, and rocks around and in the surroundings of the traps. The recaptures after marking were successful (138 recaptures over the study). The marking made it possible to detect for 14.5% of the recaptures significant movements of adults (up to 168 m) and nymphs (up to 34 m). Some bugs (nymphs and females) were recaptured after 5 months. For adults, recaptures (46 in total) mostly occurred between September and March. Females were recaptured twice as frequently as males. Conclusion The Andean wild populations of T. infestans showed a strong spatial and temporal stability during the year-long study. Dispersal may occur mainly during the rainy season. The capture-mark-recapture method was successful and the longevity of the bugs and the distances covered by nymphs and adults were recorded.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Simone Frédérique Brenière
- IRD, Institut de Recherche pour le Développement, UMR INTERTRYP (IRD-CIRAD), Interactions hôtes-vecteurs-parasites dans les infections par trypanosomatidae), 911 Av, Agropolis, 34394 Montpellier, cédex 5, France.
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Espinoza N, Borrás R, Abad-Franch F. Chagas disease vector control in a hyperendemic setting: the first 11 years of intervention in Cochabamba, Bolivia. PLoS Negl Trop Dis 2014; 8:e2782. [PMID: 24699407 PMCID: PMC3974664 DOI: 10.1371/journal.pntd.0002782] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 02/24/2014] [Indexed: 11/25/2022] Open
Abstract
Background Chagas disease has historically been hyperendemic in the Bolivian Department of Cochabamba. In the early 2000s, an extensive vector control program was implemented; 1.34 million dwelling inspections were conducted to ascertain infestation (2000–2001/2003–2011), with blanket insecticide spraying in 2003–2005 and subsequent survey-spraying cycles targeting residual infestation foci. Here, we assess the effects of this program on dwelling infestation rates (DIRs). Methodology/Principal Findings Program records were used to calculate annual, municipality-level aggregate DIRs (39 municipalities); very high values in 2000–2001 (median: 0.77–0.69) dropped to ∼0.03 from 2004 on. A linear mixed model (with municipality as a random factor) suggested that infestation odds decreased, on average, by ∼28% (95% confidence interval [CI95] 6–44%) with each 10-fold increase in control effort. A second, better-fitting mixed model including year as an ordinal predictor disclosed large DIR reductions in 2001–2003 (odds ratio [OR] 0.11, CI95 0.06–0.19) and 2003–2004 (OR 0.22, CI95 0.14–0.34). Except for a moderate decrease in 2005–2006, no significant changes were detected afterwards. In both models, municipality-level DIRs correlated positively with previous-year DIRs and with the extent of municipal territory originally covered by montane dry forests. Conclusions/Significance Insecticide-spraying campaigns had very strong, long-lasting effects on DIRs in Cochabamba. However, post-intervention surveys consistently detected infestation in ∼3% of dwellings, underscoring the need for continuous surveillance; higher DIRs were recorded in the capital city and, more generally, in municipalities dominated by montane dry forest – an eco-region where wild Triatoma infestans are widespread. Traditional strategies combining insecticide spraying and longitudinal surveillance are thus confirmed as very effective means for area-wide Chagas disease vector control; they will be particularly beneficial in highly-endemic settings, but should also be implemented or maintained in other parts of Latin America where domestic infestation by triatomines is still commonplace. Chagas disease is among the most serious public health problems in Latin America; the highest prevalence of infection by its causative agent, the parasite Trypanosoma cruzi, has historically been recorded in some parts of Bolivia. In the early 2000s, a massive insecticide-spraying program was set up to control dwelling infestation by the blood-sucking bugs that transmit the disease. Here we provide a detailed assessment of the effects of this program in the Department of Cochabamba, one of the most highly-endemic settings worldwide. Our analyses show that municipality-level dwelling infestation rates plummeted from over 70–80% in 2001–2003 to about 2–3% in 2004–2011. This residual infestation was higher in the capital city and, more generally, in municipalities where montane dry forests dominate – probably because wild populations of the main vector, Triatoma infestans, are common in that eco-region. Despite the impressive early achievements of the program, with about 0.5 million people protected from contagion, sustained disease control will require fully operational long-term surveillance systems.
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Affiliation(s)
- Natalisisy Espinoza
- Departamento de Microbiología y Ecología, Facultad de Medicina y Odontología, Universitat de València, Valencia, Spain
| | - Rafael Borrás
- Departamento de Microbiología y Ecología, Facultad de Medicina y Odontología, Universitat de València, Valencia, Spain
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Brenière SF, Salas R, Buitrago R, Brémond P, Sosa V, Bosseno MF, Waleckx E, Depickère S, Barnabé C. Wild populations of Triatoma infestans are highly connected to intra-peridomestic conspecific populations in the Bolivian Andes. PLoS One 2013; 8:e80786. [PMID: 24278320 PMCID: PMC3835561 DOI: 10.1371/journal.pone.0080786] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/07/2013] [Indexed: 11/25/2022] Open
Abstract
Triatoma infestans, the major vector of Chagas disease south of the Amazon in South America, has a large distribution of wild populations, contrary to what has previously been stated. These populations have been suspected of being the source of reinfestation of human habitats and could impede the full success of vector control campaigns. This study examined gene flow between intra-peridomestic populations and wild populations collected in the surround areas in three Andean localities in Bolivia. The populations were defined according to temporal, ecological, and spatial criteria. After DNA extraction from the legs of each insect, the samples were analyzed using seven microsatellite markers. First, the analysis of molecular variance (AMOVA) detected an absence of differentiation between wild and intra-peridomestic populations, although strong structuring was observed between the populations within each environment. Then for some populations, the Bayesian method of assignment to inferred populations showed very similar assignment patterns of the members of wild or intra-peridomestic populations in each locality. Finally, the detection of the first-generation migrants within the different populations provided evidence of insect displacement from the wild to the intra-peridomestic environment. This result indicates that, after control campaigns in the Andes, controlling this new paradigm of vector transmission risk stemming from the invasion of human habitats by wild populations of T. infestans requires long-term maintenance of public monitoring to keep the risk at a minimal level. Since wild populations of T. infestans have also been detected elsewhere in Argentina, Paraguay, and Chile, there is an urgent need to take these populations into account in future monitoring of Chagas disease transmission.
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Affiliation(s)
- Simone Frédérique Brenière
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
- Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, La Paz, Bolivia
- * E-mail:
| | - Renata Salas
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
- Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, La Paz, Bolivia
| | - Rosio Buitrago
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
- Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, La Paz, Bolivia
| | - Philippe Brémond
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
| | - Victor Sosa
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
- Instituto de Investigaciones Biomédicas y de Interacción Social (IIBISMED), Facultad de Medicina, Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Marie-France Bosseno
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
- Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, La Paz, Bolivia
| | - Etienne Waleckx
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
- Laboratorio de Parasitología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Mérida, Yucatán, México
| | - Stéphanie Depickère
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
- Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, La Paz, Bolivia
| | - Christian Barnabé
- Health Department, MIVEGEC (Université de Montpellier 1 et 2, CNRS 5290, IRD 224), Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle, Institut de recherche pour le développement (IRD), Montpellier, France
- Instituto Nacional de Laboratorios de Salud (INLASA), Laboratorio de Entomología Médica, La Paz, Bolivia
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Depickère S, Buitrago R, Siñani E, Baune M, Monje M, Lopez R, Waleckx E, Chavez T, Brenière SF. Susceptibility and resistance to deltamethrin of wild and domestic populations of Triatoma infestans (Reduviidae: Triatominae) in Bolivia: new discoveries. Mem Inst Oswaldo Cruz 2013; 107:1042-7. [PMID: 23295756 DOI: 10.1590/s0074-02762012000800013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/06/2012] [Indexed: 11/22/2022] Open
Abstract
Bolivia is a high-endemic country for Chagas disease, for which the principal vector is Triatoma infestans (Triatominae). This is a mainly domestic species that is also found in the wild environment. Recently, an increasing number of studies have shown the importance of Triatominae resistance to insecticides, especially in Bolivia. Data regarding the susceptibility/resistance of wild and domestic populations of T. infestans to deltamethrin are presented. For the first time, domestic populations of the department of Santa Cruz were tested, showing low resistance. Although most of the wild populations were found to be susceptible to deltamethrin, three populations from three departments showed a mortality rate of less than 100%. This result is emphasised here.
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Affiliation(s)
- Stéphanie Depickère
- Maladies Infectieuses et Vecteurs Écologie, Génétique, Évolution et Contrôle, Université de Montpellier 1 et 2, Centre National de Recherche Scientifique 5290, Institut de Recherche pour Développement 224, Representation in Bolivia, La Paz, Bolivia.
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Gurevitz JM, Gaspe MS, Enriquez GF, Provecho YM, Kitron U, Gürtler RE. Intensified surveillance and insecticide-based control of the Chagas disease vector Triatoma infestans in the Argentinean Chaco. PLoS Negl Trop Dis 2013; 7:e2158. [PMID: 23593525 PMCID: PMC3623707 DOI: 10.1371/journal.pntd.0002158] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 02/27/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The elimination of Triatoma infestans, the main Chagas disease vector in the Gran Chaco region, remains elusive. We implemented an intensified control strategy based on full-coverage pyrethroid spraying, followed by frequent vector surveillance and immediate selective insecticide treatment of detected foci in a well-defined rural area in northeastern Argentina with moderate pyrethroid resistance. We assessed long-term impacts, and identified factors and procedures affecting spray effectiveness. METHODS AND FINDINGS After initial control interventions, timed-manual searches were performed by skilled personnel in 4,053 sites of 353-411 houses inspected every 4-7 months over a 35-month period. Residual insecticide spraying was less effective than expected throughout the three-year period, mainly because of the occurrence of moderate pyrethroid resistance and the limited effectiveness of selective treatment of infested sites only. After initial interventions, peridomestic infestation prevalence always exceeded domestic infestation, and timed-manual searches consistently outperformed householders' bug detection, except in domiciles. Most of the infestations occurred in houses infested at baseline, and were restricted to four main ecotopes. Houses with an early persistent infestation were spatially aggregated up to a distance of 2.5 km. An Akaike-based multi-model inference approach showed that new site-level infestations increased substantially with the local availability of appropriate refugia for triatomine bugs, and with proximity to the nearest site found infested at one or two preceding surveys. CONCLUSIONS AND SIGNIFICANCE Current vector control procedures have limited effectiveness in the Gran Chaco. Selective insecticide sprays must include all sites within the infested house compound. The suppression of T. infestans in rural areas with moderate pyrethroid resistance requires increased efforts and appropriate management actions. In addition to careful, systematic insecticide applications, housing improvement and development policies that improve material conditions of rural villagers and reduce habitat suitability for bugs will contribute substantially to sustainable vector and disease control in the Gran Chaco.
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Affiliation(s)
- Juan M. Gurevitz
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Sol Gaspe
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gustavo F. Enriquez
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Yael M. Provecho
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Uriel Kitron
- Department of Environmental Studies, Emory University, Atlanta, Georgia, United States of America
| | - Ricardo E. Gürtler
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
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Gaspe MS, Gurevitz JM, Gürtler RE, Dujardin JP. Origins of house reinfestation with Triatoma infestans after insecticide spraying in the Argentine Chaco using wing geometric morphometry. INFECTION GENETICS AND EVOLUTION 2013; 17:93-100. [PMID: 23557838 DOI: 10.1016/j.meegid.2013.03.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/01/2013] [Accepted: 03/25/2013] [Indexed: 10/27/2022]
Abstract
Identifying the origins of insect vectors collected after community-wide residual insecticide applications is a relevant challenge in the Gran Chaco region where the main vector of Chagas disease Triatoma infestans usually reinfests human dwellings. Wing geometric morphometry was used to compare the right wings of 63 males and 54 females collected at 4 months post-spraying (MPS) with those from 165 males and 111 females collected before full-coverage spraying with pyrethroids in a well-defined rural area in Northeastern Argentina. Male and female wing centroid size resulted significantly larger at 4MPS than before interventions, but no significant changes in shape were detected. Metric disparity (variance of shape) varied significantly in males but not in females. Using shape variables, a relatively large fraction of post-spraying males (70%) and females (54%) could not be differentiated from those collected at the same source house or at the nearest infested house before interventions. Bugs collected at 4 and 8MPS in a persistently infested house were mainly assigned to the source house. These results support the hypothesis of persistent bug populations that survived the insecticide application at local spatial scales, and are consistent with the occurrence of vector control failures most likely related to moderate pyrethroid resistance. Wing geometric morphometry is a useful tool for identifying sources of reinfestation, but it is limited by the spatial structure found in the reference populations. Combined with field and genetic data, this approach may contribute to the understanding of the reinfestation process and improvement of vector control strategies.
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Affiliation(s)
- M Sol Gaspe
- Laboratorio de Eco-Epidemiología, Depto. de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires-IEGEBA, CONICET-UBA, Ciudad Universitaria, 1428EHA Buenos Aires, Argentina
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Lardeux F. Niche invasion, competition and coexistence amongst wild and domestic Bolivian populations of Chagas vector Triatoma infestans (Hemiptera, Reduviidae, Triatominae). C R Biol 2013; 336:183-93. [DOI: 10.1016/j.crvi.2013.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 11/30/2022]
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Orozco MM, Enriquez GF, Alvarado-Otegui JA, Cardinal MV, Schijman AG, Kitron U, Gürtler RE. New sylvatic hosts of Trypanosoma cruzi and their reservoir competence in the humid Chaco of Argentina: a longitudinal study. Am J Trop Med Hyg 2013; 88:872-82. [PMID: 23530075 DOI: 10.4269/ajtmh.12-0519] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A four-year longitudinal study of the structure of sylvatic transmission cycles of Trypanosoma cruzi, reservoir host competence and parasite discrete typing units was conducted in a disturbed rural area of the humid Chaco in Argentina. Among 190 mammals examined by xenodiagnosis and polymerase chain reaction amplification, the composite prevalence of infection was substantially higher in Dasypus novemcinctus armadillos (57.7%) and Didelphis albiventris opossums (38.1%) than in Euphractus sexcinctus (20.0%), Tolypeutes matacus (12.5%), and Chaetophractus vellerosus (6.3%) armadillos. Trypanosoma cruzi was detected for the first time in Thylamys pusilla small opossums and in two unidentified small rodents. Infection was spatially aggregated only in armadillos. All Didelphis were infected with T. cruzi I and all armadillo species were infected with T. cruzi III, implying two distinct sylvatic cycles with no inputs from the domestic cycle. Dasypus armadillos and Didelphis opossums were much more infectious to vectors than other armadillos, small opossums, or rodents.
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Affiliation(s)
- M Marcela Orozco
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
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Abstract
After remarkable reduction in prevalence through regional elimination of domestic vectors, the central challenge of Chagas disease control is shifting towards interruption of the disease transmission by non-eliminable vectors in Latin America. Vector surveillance with community participation was cost-effective against the eliminable vectors. But the efforts often failed against the non-eliminable vectors due to lack of surveillance coverage or sustainability. For instance, in El Salvador and Honduras, the operational vector control personnel lost access to many communities under decentralized health systems. To cover wider areas lastingly, the countries implemented the surveillance systems involving non-specialists from locally embedded resources, such as local health services, schools and community leaders. From these experiences, this paper outlines a common structure of the current community-based surveillance systems, consisting of five fundamental sequential functions. To increase scalability and sustainability, four of the five functions could be delegated to the locally available human resources, and the surveillance systems can be integrated into the general health systems. Challenges at national and regional levels are discussed for further evolution of the surveillance systems.
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Affiliation(s)
- Ken Hashimoto
- University of Calgary, Faculty of Veterinary Medicine, Calgary, Alberta, Canada
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Alvarado-Otegui J, Ceballos L, Orozco M, Enriquez G, Cardinal M, Cura C, Schijman A, Kitron U, Gürtler R. The sylvatic transmission cycle of Trypanosoma cruzi in a rural area in the humid Chaco of Argentina. Acta Trop 2012; 124:79-86. [PMID: 22771688 DOI: 10.1016/j.actatropica.2012.06.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 06/22/2012] [Accepted: 06/26/2012] [Indexed: 01/01/2023]
Abstract
Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species were captured and examined for infection by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively.
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Mota T, Lorenzo MG. Lack of segregation between two species of Chagas disease vectors. Am J Trop Med Hyg 2012; 87:109-16. [PMID: 22764300 PMCID: PMC3391033 DOI: 10.4269/ajtmh.2012.11-0168] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 12/01/2011] [Indexed: 11/07/2022] Open
Abstract
Triatoma infestans and Panstrongylus megistus are relevant Chagas disease vectors. An apparent segregation among these triatomine species inside human households was suggested to rely on mutual repellence between them. However, P. megistus and T. infestans show aggregation responses to chemical signals emitted by the other species. These findings do not rule out the possibility that stimuli other than chemical signals could mediate repellence when these species exploit shelters simultaneously. In the present study, we investigated how P. megistus and T. infestans exploit shelters in controlled laboratory conditions and how insect density and environmental illumination modulate this behavior. We evaluated whether these species aggregate inside shelters or mutually repel each other. Panstrongylus megistus and T. infestans show specific patterns of shelter exploitation, which are differentially affected by insect density and environment illumination. In particular, P. megistus is more sensitive to insect density than T. infestans, whereas T. infestans shows higher sensitivity to illumination than P. megistus. Nevertheless, these species exploit shelters randomly without any apparent repellence.
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Affiliation(s)
- Theo Mota
- Laboratório de Triatomíneos e Epidemiologia da Doença de Chagas, Centro de Pesquisas René Rachou, FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil.
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Genetic characterization of Trypanosoma cruzi DTUs in wild Triatoma infestans from Bolivia: predominance of TcI. PLoS Negl Trop Dis 2012; 6:e1650. [PMID: 22685616 PMCID: PMC3368956 DOI: 10.1371/journal.pntd.0001650] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 04/07/2012] [Indexed: 11/20/2022] Open
Abstract
Background The current persistence of Triatoma infestans (one of the main vectors of Chagas disease) in some domestic areas could be related to re-colonization by wild populations which are increasingly reported. However, the infection rate and the genetic characterization of the Trypanosoma cruzi strains infecting these populations are very limited. Methodology/Principal Findings Of 333 wild Triatoma infestans specimens collected from north to south of a Chagas disease endemic area in Bolivia, we characterized 234 stocks of Trypanosoma cruzi using mini-exon multiplex PCR (MMPCR) and sequencing the glucose phosphate isomerase (Gpi) gene. Of the six genetic lineages (“discrete typing units”; DTU) (TcI-VI) presently recognized in T. cruzi, TcI (99.1%) was overdominant on TcIII (0.9%) in wild Andean T. infestans, which presented a 71.7% infection rate as evaluated by microscopy. In the lowlands (Bolivian Chaco), 17 “dark morph” T. infestans were analyzed. None of them were positive for parasites after microscopic examination, although one TcI stock and one TcII stock were identified using MMPCR and sequencing. Conclusions/Significance By exploring large-scale DTUs that infect the wild populations of T. infestans, this study opens the discussion on the origin of TcI and TcV DTUs that are predominant in domestic Bolivian cycles. Chagas disease is a neglected parasitic disease transmitted by bugs (vectors) and represents a serious health problem in the Americas. Although the transmission generally occurs in the houses where the bugs are living, wild populations of vectors are now considered a problem because these populations might enter the houses and recolonize them after eliminating of house populations by insecticide spraying. This is the case of the Southern countries where Triatoma infestans, the principal vector, transmits Trypanosoma cruzi the agent of the disease. This parasite presents a large genetic variability and it is important to know which T. cruzi genotypes are carried by the vectors. The authors found that in the wild T. infestans from the Bolivian Andean region, a principal group of genotype was circulating. In the lowlands (Bolivian Chaco), another additional genotype group was detected. Together with exploring at large scale which genotypes are infecting T. infestans wild populations, this study opens the discussion on the origin T. cruzi genotype groups. Also this study completes our basic knowledge on T. cruzi subspecific genetic variability, and therefore brings new tools for molecular epidemiology of Chagas disease.
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Waleckx E, Depickère S, Salas R, Aliaga C, Monje M, Calle H, Buitrago R, Noireau F, Brenière SF. New discoveries of sylvatic Triatoma infestans (Hemiptera: Reduviidae) throughout the Bolivian Chaco. Am J Trop Med Hyg 2012; 86:455-8. [PMID: 22403316 DOI: 10.4269/ajtmh.2012.11-0205] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Sylvatic populations of Triatoma infestans might be involved in the recolonization of human dwellings. We report here the discoveries of new T. infestans sylvatic foci in the Bolivian Chaco. Eighty-one triatomines were caught, 38 of which were identified as T. infestans. Triatoma sordida and Panstrongylus geniculatus were the other species collected. One T. infestans and one T. sordida were infected with Trypanosoma cruzi TcI; one T. infestans was infected with TcII. These discoveries add to the debate on the geographic distribution of sylvatic T. infestans populations, the geographic origin of the species, and the epidemiological role of these populations.
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Affiliation(s)
- Etienne Waleckx
- Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, Université Montpellier - CNRS - IRD, Institut de Recherche pour le Développement, La Paz, Bolivia.
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Moreno ML, Hoyos L, Cabido M, Catalá SS, Gorla DE. Exploring the association between Trypanosoma cruzi infection in rural communities and environmental changes in the southern Gran Chaco. Mem Inst Oswaldo Cruz 2012; 107:231-7. [DOI: 10.1590/s0074-02762012000200013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 12/01/2011] [Indexed: 11/22/2022] Open
Affiliation(s)
- Mariana Laura Moreno
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica, Argentina
| | | | | | - Silvia Susana Catalá
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica, Argentina
| | - David Eladio Gorla
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica, Argentina
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Ceballos LA, Piccinali RV, Marcet PL, Vazquez-Prokopec GM, Cardinal MV, Schachter-Broide J, Dujardin JP, Dotson EM, Kitron U, Gürtler RE. Hidden sylvatic foci of the main vector of Chagas disease Triatoma infestans: threats to the vector elimination campaign? PLoS Negl Trop Dis 2011; 5:e1365. [PMID: 22039559 PMCID: PMC3201917 DOI: 10.1371/journal.pntd.0001365] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 09/05/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Establishing the sources of reinfestation after residual insecticide spraying is crucial for vector elimination programs. Triatoma infestans, traditionally considered to be limited to domestic or peridomestic (abbreviated as D/PD) habitats throughout most of its range, is the target of an elimination program that has achieved limited success in the Gran Chaco region in South America. METHODOLOGY/PRINCIPAL FINDINGS During a two-year period we conducted semi-annual searches for triatomine bugs in every D/PD site and surrounding sylvatic habitats after full-coverage spraying of pyrethroid insecticides of all houses in a well-defined rural area in northwestern Argentina. We found six low-density sylvatic foci with 24 T. infestans in fallen or standing trees located 110-2,300 m from the nearest house or infested D/PD site detected after insecticide spraying, when house infestations were rare. Analysis of two mitochondrial gene fragments of 20 sylvatic specimens confirmed their species identity as T. infestans and showed that their composite haplotypes were the same as or closely related to D/PD haplotypes. Population studies with 10 polymorphic microsatellite loci and wing geometric morphometry consistently indicated the occurrence of unrestricted gene flow between local D/PD and sylvatic populations. Mitochondrial DNA and microsatellite sibship analyses in the most abundant sylvatic colony revealed descendents from five different females. Spatial analysis showed a significant association between two sylvatic foci and the nearest D/PD bug population found before insecticide spraying. CONCLUSIONS Our study shows that, despite of its high degree of domesticity, T. infestans has sylvatic colonies with normal chromatic characters (not melanic morphs) highly connected to D/PD conspecifics in the Argentinean Chaco. Sylvatic habitats may provide a transient or permanent refuge after control interventions, and function as sources for D/PD reinfestation. The occurrence of sylvatic foci of T. infestans in the Gran Chaco may pose additional threats to ongoing vector elimination efforts.
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Affiliation(s)
- Leonardo A. Ceballos
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Romina V. Piccinali
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Paula L. Marcet
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Atlanta, Georgia, United States of America
| | - Gonzalo M. Vazquez-Prokopec
- Department of Environmental Studies, Emory University, Atlanta, Georgia, United States of America
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
| | - M. Victoria Cardinal
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Judith Schachter-Broide
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jean-Pierre Dujardin
- Unité Mixte de Recherche, Institut de Recherches pour le Développment-Centre National de Recherche Scientifique, Montpellier, France
| | - Ellen M. Dotson
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Atlanta, Georgia, United States of America
| | - Uriel Kitron
- Department of Environmental Studies, Emory University, Atlanta, Georgia, United States of America
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ricardo E. Gürtler
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina
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Nattero J, Leonhard G, Rodríguez CS, Crocco L. Influence of the quality and quantity of blood ingested on reproductive parameters and life-span in Triatoma infestans (Klug). Acta Trop 2011; 119:183-7. [PMID: 21672510 DOI: 10.1016/j.actatropica.2011.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 05/26/2011] [Accepted: 05/29/2011] [Indexed: 10/18/2022]
Abstract
In Triatominae, female fecundity and fertility may be affected by age, adult nutritional status (i.e., blood meal source and amount of blood ingested) and number of matings. Triatoma infestans (Klug) is the main vector of Chagas disease in southern South America and considering that reproductive success is intimately associated with the potential for colonizing or re-colonizing new ecotopes in endemic areas, we studied whether the blood meal source and the amount of blood ingested have influence on reproductive parameters. We constitute two groups: couples feeding regularly on guinea pigs and couples feeding regularly on pigeons. We registered quantity of blood ingested, fecundity, fertility, number of matings, days between the first feeding and mating, copula initiation, oviposition initiation and adult life-span. Results showed that females that fed on guinea pigs exhibited high fecundity and fertility, higher number of matings and they needed a lower amount of blood to form an egg. The number of matings and fecundity increased linearly and significantly with the quantity of blood ingested for both meal sources. Results from lineal regression between life-span and fecundity showed a positive and significant relation for both meal sources. The number of matings showed a positive relation with fecundity for both meal sources but significant only for guinea pigs. In T. infestans, the quantity of blood ingested could be a determinant of their reproductive efficiency. This species is mainly adapted to human dwelling and peridomestic structures where there is low host diversity. Considering that this species is in contact with mammals over other food sources, a greater reproductive success may result from an adaptation to this environment.
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Sarquis O, Oliveira LS, Rego R, Gonçalves JM, Lima MM, Maciel-de-Freitas R. Evaluation of RbCl and CrCl₃ as markers of Triatoma brasiliensis (Hemiptera: Reduviidae) nymphs: persistence and influence of Rb and Cr on triatomine biology. Mem Inst Oswaldo Cruz 2011; 106:385-9. [PMID: 21739023 DOI: 10.1590/s0074-02762011000400001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 12/16/2010] [Indexed: 11/22/2022] Open
Abstract
In order to mark Triatoma brasiliensis, the vector of Chagas disease in Brazil, two chemical compounds, rubidium chloride (RbCl) and chromium chloride (CrCl₃), were tested. First, 199 N2-N5 nymphs were fed on blood with 0.025M RbCl. Rb marker positivity ranged from 2.5% (N3)-70% (N2), with a maximum persistence of 98 days. Second, 265 N2-N5 nymphs were fed on blood containing 0.0015M CrCl₃. Cr marker positivity ranged up to 93% (N5), with a maximum persistence of 119 days. Finally, we blood fed 213 T. brasiliensis to investigate whether CrCl₃ altered the biology of this insect. The developmental time of T. brasiliensis was unaltered, but the survival of the Cr-marked group was lower than that of the control group. Differences in the mean fecundity of the control (mean of 156.1) and experimental (mean of 135.6) groups were not statistically significant and 100% of the egg batches of females Cr-marked as nymphs were positive. In conclusion, CrCl₃ is a useful tool for marking T. brasiliensis nymphs due to its high positivity and persistence.
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Affiliation(s)
- Otília Sarquis
- Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
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Piccinali RV, Marcet PL, Ceballos LA, Kitron U, Gürtler RE, Dotson EM. Genetic variability, phylogenetic relationships and gene flow in Triatoma infestans dark morphs from the Argentinean Chaco. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2011; 11:895-903. [PMID: 21352954 PMCID: PMC3104122 DOI: 10.1016/j.meegid.2011.02.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 02/10/2011] [Accepted: 02/15/2011] [Indexed: 11/18/2022]
Abstract
The recent discovery of sylvatic populations of Triatoma infestans outside the Andean Valleys of Bolivia prompted an evolutionary question about the putative ancestral area of origin and dispersal of the species, and an epidemiological question regarding the possible role of these sylvatic populations in the recolonization process of insecticide-treated houses. The finding of a population of sylvatic melanic T. infestans (dark morphs) in the Argentinean dry Chaco at 7 km from a peridomestic bug population of typical coloration gave us the opportunity to test both questions simultaneously by employing phylogenetic and population genetic approaches. For this purpose we analyzed sylvatic and peridomestic bugs using sequence-based mitochondrial and nuclear markers (mtCOI and ITS-1) and microsatellites. Sylvatic bugs were confirmed to be T. infestans and not hybrids, and showed high levels of genetic variability and departures from neutral expectations for mtCOI variation. New ITS-1 and mtCOI haplotypes were recorded, as well as haplotypes shared with peridomestic and/or domestic bugs from previous records. The peridomestic population was invariant for ITS-1 and mtCOI, but showed variability for microsatellites and signatures of a population bottleneck, probably due to a limited number of founders. Phylogenetic analyses were consistent with the presence of ancestral haplotypes in sylvatic bugs. According to F-statistics and assignment methods there was a significant differentiation between sylvatic and peridomestic bugs and gene flow was low and asymmetric, with more bugs moving from the peridomicile to the sylvatic environment. These results support the hypothesis of the Chaco region as the area of origin of T. infestans, and a limited role of sylvatic melanic T. infestans in peridomestic infestation in the Argentinean Chaco.
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Affiliation(s)
- R V Piccinali
- Laboratorio de Eco-Epidemiología, Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
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